从另一个 .swift 文件调用 ViewController 函数

Question

我有一个 collectionView，我想在收到某些数据后 reloadData()。问题是：我不知道如何从另一个处理数据的 .swift 文件调用 ViewController 函数。我尝试这样做：

class WebSocketLogic: WebSocketDelegate {
    var viewController = ViewController()
    var columns = 0
    var rows = 0
...
    func receiveData {
        ...
        columns = map.count
        rows = map[0].count
        viewController.collectionView.reloadData()
    }
}

它在 ViewController() 初始化行上给了我 Thread 1: EXC_BAD_ACCESS (code=2, address=0x7ffeec870fe8) 错误。
我也试过做：

class ViewController: UIViewController {
    
    @IBOutlet weak var collectionView: UICollectionView!
    
    var webSocket = WebSocketLogic(roomId: 1)
    var columns = 0 {
        didSet {
            collectionView.reloadData()
            print("columns number set to: \(columns)")
        }
    }
    var rows = 0  

    override func viewDidLoad() {
        super.viewDidLoad()
        
        webSocket.setupStarScream()
        columns = webSocket.columns
        rows = webSocket.rows
    }
}

但由于某种原因，didSet 只在一开始就被调用一次。一旦 receiveData()func 在另一个文件中完成，我该如何调用 ViewController 中的 reloadData()？

Answer 1

您可以使用delegation pattern

protocol DataDelegate {
    func dataReceived()
}

class WebSocketLogic: WebSocketDelegate {
    var delegate: DataDelegate?
    var columns = 0
    var rows = 0
...
    func receiveData {
        ...
        columns = map.count
        rows = map[0].count
        delegate?.dataReceived()
    }
}

class ViewController: UIViewController, DataDelegate {
    
    @IBOutlet weak var collectionView: UICollectionView!
    
    var webSocket = WebSocketLogic(roomId: 1)
    var columns = 0 {
        didSet {
            collectionView.reloadData()
            print("columns number set to: \(columns)")
        }
    }
    var rows = 0  

    override func viewDidLoad() {
        super.viewDidLoad()
        webSocket.delegate = self
        
        webSocket.setupStarScream()
        columns = webSocket.columns
        rows = webSocket.rows
    }
   
    func dataReceived() {
        collectionView.reloadData()
    }
}

从另一个 .swift 文件调用 ViewController 函数

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